Catalyst formulations with reduced leachable salts

ABSTRACT

Embodiments of the present technology may include a carbohydrate binder composition. The carbohydrate binder composition may include a carbohydrate, a nitrogen-containing compound, and a catalyst. The catalyst may catalyze a reaction between the carbohydrate and the nitrogen-containing compound. The catalyst may be water soluble in the composition but may become water insoluble after curing the composition.

BACKGROUND

For decades, urea formaldehyde (UF), phenol formaldehyde (PF), andmelamine formaldehyde (MF) binder compositions have been used to makeglass fiber mats for building materials, including insulation, flooring,siding, facers, and roofing shingles. UF binders were favored for thesematerials because of their low cost and acceptable strength properties.For materials like roofing shingles, the UF in the binder compositionswere often blended with more flexible latex polymers such as polyvinylacetate, vinyl acrylic, and/or styrene butadiene polymers. The latexesin the binders gave the shingles increased tensile and tear strength, aswell as improved their moisture resistance properties.

More recently, the construction industry has moved away fromformaldehyde-based binder compositions. Formaldehyde is considered aprobable human carcinogen, as well as an irritant and an allergen, andits use in binder formulations for building products, textiles,upholstery, and other materials is increasingly restricted. Thus, makersof building materials have been developing alternative binderformulations that are formaldehyde free.

One alternative binder system that has received considerable attentionincludes the polymerization of carbohydrates (i.e., sugars) with aminecompounds to make a binder that is insoluble in water and adheres wellto glass fibers. In addition to being formaldehyde-free, thesecarbohydrate-based binder formulations can be made from renewably grownnatural sugars instead of non-renewable, petroleum-based feedstocks.

Compounds used in the processing of formaldehyde-free binder systems andin making formaldehyde-free fiber composites may ultimately weaken thecomposite or materials near the composite. Thus, there is a need foralternative compositions and methods to produce formaldehyde-free fibercomposites.

BRIEF SUMMARY

Embodiments of the present technology may catalyze Maillard reactions inbinder compositions without significant leaching of the catalyst and itsderivatives from the finished product. The catalyst may include polymersor oligomers with sulfate or phosphate moieties that are initially watersoluble but become water insoluble after curing, making the leaching ofthe salts from a finished product less likely. These catalysts may notform acids when exposed to water and may then reduce corrosion. Thecatalysts also may reduce delamination between glass fibers and thebinder composition, possibly as a result of not forming acids that reactwith the glass fibers.

Embodiments of the present technology may include a carbohydrate bindercomposition. The carbohydrate binder composition may include acarbohydrate, a nitrogen-containing compound, and a catalyst. Thecatalyst may catalyze a reaction between the carbohydrate and thenitrogen-containing compound. The catalyst may be water soluble in thecomposition but may become water insoluble after curing the composition.

Embodiments of the present technology may include a method of reducingleaching from a fiber-containing composite. The method may includeforming an aqueous dispersion of fibers. The method may further includeapplying a binder composition to the aqueous dispersion of fibers toform a binder-fiber mixture. The binder composition may include acarbohydrate, a nitrogen-containing compound, and a catalyst thatcatalyzes the reaction between the carbohydrate and thenitrogen-containing compound. The catalyst may be water soluble beforecuring but water insoluble after curing. In addition, the method mayinclude curing the binder-fiber mixture to form the fiber-containingcomposite.

Embodiments of the present technology may also include afiber-containing composite. The fiber-containing composite may includeglass fibers and a binder. The binder may include cured products from acarbohydrate binder composition. The carbohydrate binder composition mayinclude a carbohydrate, a nitrogen-containing compound, and a catalystthat catalyzes a reaction between the carbohydrate and thenitrogen-containing compound. The nitrogen-containing compound may be anamino-amide, an amine salt of an organic acid, an ammonium salt of acarboxylic acid, or a reaction product of a urea compound and analdehyde-containing compound. The catalyst may be water insoluble in thefiber-containing composite. The fiber-containing composite may have aleach rate of ions that is less than a leach rate of ions from afiber-containing composite with a sulfate, phosphate, or nitrate saltsubstituted for the catalyst.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block flow diagram of a method of reducing leachingaccording to embodiments of the present technology.

FIGS. 2A-C show simplified illustrations of exemplary compositematerials according to embodiments of the present technology.

DETAILED DESCRIPTION

Various thermosetting binders have moved from includingformaldehyde-based binders to binders that include polycarboxylic acidscrosslinked with products of a Maillard reaction. Conventional, Maillardreaction catalysts may include sulfate, phosphate, nitrate, orcarboxylate salts. These salts may be used in an amount from about 2.5%to 15% based on the mass of the solid resin. The catalyst salts may notbe consumed during the curing process, and as a result may be presentthroughout the process and in the final product. These salts may leachout of the binder composition or the cured article. In particular, saltsthat contain sulfates or phosphates may react with water to form acids,such as sulfuric acid or phosphoric acid. These acids may lead tocorrosion during the process or in the final product. These leached ionsalso may often be hygroscopic, which may increase the amount of waterpresent, which may then increase the amount of leaching of the ions, andthus, may create a reinforcing feedback loop, increasing corrosion.

Additionally, the catalysts may affect glass that should be heldtogether by the binder resins. The surface of glass fibers may includesilicates, such as sodium, potassium, magnesium, aluminum, and boronsilicates. Acids, such as sulfuric acid, may compete with the metal ionsfor the silicates. Acids may convert silicate to silica, affecting theproperties of the glass surface. By reducing the metals and silicateconcentrations on the glass surfaces, the glass surfaces may not be asstable for binding with the resin. The catalysts may affect theinterface between the resin and the glass and cause delamination.

Embodiments of the present technology may include catalysts that havesulfate or phosphate moieties but not as part of salts. The sulfates andphosphate moieties may be attached to a polymer or oligomer and may beinsoluble in water after curing. The catalysts may be completelyinsoluble or have a trace level of solubility. As a result, catalysts ofthe present technology may not leach out of a cured article and may notform acids that may reduce cure kinetics, mechanical strength, impactresistance, and other properties of the resin or the final product.

Embodiments of the present technology may include a carbohydrate bindercomposition. The carbohydrate binder composition may include acarbohydrate, a nitrogen-containing compound, and a catalyst. Thecarbohydrate and nitrogen-containing compound are described later inthis specification. Embodiments may include or exclude any carbohydrate,nitrogen-containing compound, group of carbohydrates, or group ofnitrogen-containing compounds described herein. The binder compositionmay be substantially or completely free of formaldehyde.

The catalyst may catalyze a reaction between the carbohydrate and thenitrogen-containing compound. The catalyst may include a sulfate, asulfonate, a phosphate, or a phosphonate moiety. The sulfate, sulfonate,phosphate, or phosphonate moiety may be attached to an organic compoundor a polymer. The catalyst may be a sulfated, sulfonated, phosphate, orphosphonated polymer with a molecular weight of about 20,000 g/mol ormore.

Catalysts may include a sulfonated polystyrene, a sulfonated styrenemaleic anhydride, a sulfonated polyethylene, a sulfonated polypropylene,a phosphonated polystyrene, a phosphonated styrene maleic anhydride, aphosphanated polyethylene, or a phosphanated polypropylene. Catalystsmay also include a sulfated polystyrene, a sulfated styrene maleicanhydride, a sulfated polyethylene, a sulfated polypropylene, aphosphated polystyrene, a phosphated styrene maleic anhydride, aphosphated polyethylene, or a phosphated polypropylene.

The catalyst may be a sulfated, sulfonated, phosphated, or phosphonatedoligomer. An oligomer may include from 2 to 100 monomers. The catalystmay include a dimer, a trimer, or a tetramer.

The catalyst may be a sulfated, sulfonated, phosphate, or a phosphanatedepoxy. The catalyst may include a reaction product of one mole of epoxyor epoxide moiety and one mole of sulfuric acid, sulfonic acid,phosphoric acid, or phosphonic acid. The epoxy may include an epoxidizedplant oil, an epoxidized polyether, bisphenol-A (BPA) epoxy, bisphenol-F(BPF) epoxy, a resole epoxy, or a novolac epoxy. The plant oil may besoybean oil or linseed oil. The catalyst may include a phosphonatedepoxidized plant oil.

The sulfated epoxy may be formed by the reaction of an acid with anepoxy and neutralized with a base. For example, BPA may be reacted withsulfuric acid and neutralized with ammonia:

Because BPA has two epoxide moieties, two moles of sulfuric acid mayreact with each mole of BPA.

Similarly, a phosphated epoxy may be formed by the reaction of an acidwith an epoxy and neutralized with a base. For example, an epoxidizedplant oil may be reacted with phosphoric acid and neutralized withammonia:

The structure of the catalyst may affect the properties of the resin andthe finished product. A highly aromatic catalyst may increase thehardness of the resin or finished product. On the other hand, a highlyaliphatic catalyst may increase the impact resistance of the resin orfinished product. The structure of the catalyst may be tailored towardthe desired properties of the resin and/or the finished product.

The pH of the composition may be from about 7 to about 12 or from about7 to about 10 in embodiments. The pH of the composition may be raised bythe addition of a base. The base may include ammonium hydroxide. Thecomposition may further include a counter ion formed by a reaction of anacid with a base. The counter ion may be ammonium. The base may includeammonia, a substituted amine, or a polyamine. The substituted amine maybe an aliphatic mono-substituted amine, an aliphatic di-substitutedamine, an aliphatic tri-substituted amine, an aromatic mono-substitutedamine, an aromatic di-substituted amine, or an aromatic tri-substitutedamine. The counter ion may have a positive charge.

The catalyst may be water soluble in the composition but may becomewater insoluble after curing the composition. Curing the composition mayinclude heating the composition to a temperature from about 100° C. toabout 250° C. The counter ion may play a role in the solubility of thecatalyst. The counter ion, when present, may aid the solubility of thecatalyst in water. During or after cure, the counter ion may no longerbe present, which may lead to the catalyst being insoluble in water. Thecounter ion may become part of the binder matrix, which may includereacting with binder components. The counter ion may be physicallytrapped or immobilized within the binder matrix. In some embodiments,the counter ion may decompose or be emitted from the binder duringcuring.

The catalyst may be insoluble in water and may not be covalently bondedto any other compounds. In some embodiments, some compounds, such assome sulfonates, may react with alcohols or sugars, and therefore mayact as a crosslinker. However, covalent bonding or crosslinking may notbe the dominant mechanism in which catalysts become immobilized orinsoluble.

The catalyst and any combination of catalysts previously described maybe part of a total catalyst package. The total catalyst package mayinclude a salt catalyst or salt catalysts. The salt catalysts maycatalyze the reaction between the carbohydrate and thenitrogen-containing compound. The salt catalyst may include sulfate,nitrate, or phosphate salts. For example, the salt catalyst may includeammonium sulfate or diammonium phosphate. The salt catalyst or saltcatalysts in the composition may have a total weight no more thanone-ninth the total weight of the catalysts that are insoluble aftercure. The insoluble catalysts may be 90 wt. % or more, 93 wt. % or more,or 95 wt. % or more of the weight of the total catalyst package on a drybasis in embodiments.

As shown in FIG. 1, embodiments of the present technology may include amethod 100 of reducing leaching from a fiber-containing composite.Method 100 may include forming an aqueous dispersion of fibers 102. Insome embodiments, method 100 may also include passing the aqueousdispersion through a mat forming screen to form a wet mat.

Method 100 may further include applying a binder composition to theaqueous dispersion of fibers to form a binder-fiber mixture 104.Applying the binder composition may include applying the bindercomposition to a wet mat to form a binder-containing wet mat. Applyingthe binder composition to the wet mat may include curtain coating thebinder composition on the wet mat.

The binder composition may include a carbohydrate, a nitrogen-containingcompound, and a catalyst that catalyzes the reaction between thecarbohydrate and the nitrogen-containing compound. The carbohydrate mayinclude a reducing sugar. The reducing sugar may include dextrose,fructose, allose, galactose, xylose, ribose, maltose, cellobiose, andlactose. In some examples, the dextrose equivalent of the sugar may be85 or more or 90 or more. The nitrogen-containing compound may include adiamine or a reaction product of a urea compound and analdehyde-containing compound. The diamine may include ethylene diamine,1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine,1,6-hexanediamine, α, α′-diaminoxylene, diethylenetriamine,triethylenetetramine, tetraethylenepentamine, or diamino benzene. Thenitrogen-containing compound may include4,5-dihydroxyimidazolidin-2-one. The carbohydrate and thenitrogen-containing compound may be any carbohydrate and anynitrogen-containing compound described herein.

The catalyst may be water soluble before curing but water insolubleafter curing. The catalyst may be any catalyst described herein. Inaddition, method 100 may include curing the binder-fiber mixture to forma fiber-containing composite 106. Curing may form a non-woven glassfiber mat or any other fiber-containing composite.

Embodiments of the present technology may also include afiber-containing composite. The fiber-containing composite may includeglass fibers and a binder. The fiber-containing composite may be a wovenor non-woven mat or any fiber-containing composite described herein. Thebinder may include cured products from a carbohydrate bindercomposition. The carbohydrate binder composition may include acarbohydrate, a nitrogen-containing compound, and a catalyst thatcatalyzes a reaction between the carbohydrate and thenitrogen-containing compound. The carbohydrate may be any carbohydratedescribed herein. The nitrogen-containing compound may be anamino-amide, an amine salt of an organic acid, an ammonium salt of acarboxylic acid, or a reaction product of a urea compound and analdehyde-containing compound. The nitrogen-containing compound may beany nitrogen-containing compound described herein. The catalyst may bewater insoluble in the fiber-containing composite. The catalyst may beany catalyst described herein. The fiber-containing composite may have aleach rate of ions that is less than a leach rate of ions from afiber-containing composite with a sulfate, phosphate, or nitrate saltsubstituted for the catalyst.

The binder compositions may be used to make fiber-containing compositesthat include woven or non-woven fibers bound together by a cured matrixof the binder. The fibers in the composite may include one or more typesof fibers chosen from glass fibers, carbon fibers, mineral fibers, andorganic polymer fibers, among other kinds for fibers. At the conclusionof the curing stage, the cured binder may be present as a secure coatingon the fiber mat at a concentration of approximately 0.5 to 50 percentby weight of the composition, for example the cured binder may bepresent at concentration of approximately 1 to 10 percent by weight ofthe composition.

The fiber-containing composites may take a variety of forms, for exampleconstruction materials including piping insulation, duct boards (e.g.,air duct boards), and building insulation, reinforcement scrim, androofing membranes, among other construction materials. Additionalexamples may include loose-fill blown insulation, duct liner, duct wrap,flexible duct media, pipe insulation, tank insulation, rigid plenumliner, textile duct liner insulation, equipment liner, oven insulation,elevated temperature board, elevated temperature wrap, elevatedtemperature panel, insulation batts and rolls, heavy density battinsulation, light density batt insulation, exterior foundationinsulation board, and marine hull insulation, among other materials. Thecomposites can also find use in printed circuit boards, batteryseparators, and filter stock, among other applications.

FIGS. 2A-C illustrate some of these exemplary composite materials. FIG.2A is a simplified schematic of an exemplary fiber-containing battmaterial 202 that may be used for building insulation. The material 202may include a batt 203 of non-woven fibers held together by the binder.The fibers may be glass fibers used to make fiberglass insulation (e.g.,low-density or high-density fiberglass insulation), or a blend of two ormore types of fibers, such as a blend of glass fibers and organicpolymer fibers, among other types of fibers. In some examples, a facer204 may be attached to one or more surfaces of the batt 203.

FIG. 2B is a simplified schematic of an exemplary fiber-containingcomposite board 206 that may be used as an insulation board, duct board,elevated temperature board, etc. The fibers in board 206 may includeglass fibers, organic polymer fibers, inorganic fibers, carbon fibers,mineral fibers, metal fibers, among other types of fibers, and blends oftwo or more types of fibers.

FIG. 2C is a simplified schematic of an exemplary fiber-containingflexible insulation material 208 that may be used as a wrap and/or linerfor ducts, pipes, tanks, equipment, etc. The fiber-containing flexibleinsulation material 208 may include a facer 210 attached to one or moresurfaces of the fiber material 212. Exemplary materials for the facer210 may include fire-resistant foil-scrim-kraft facing.

Specific examples of fiber-containing composites that use the presentbinder compositions include low-density fiberglass insulation (e.g.,less than about 0.5 lbs/ft³) and high-density fiberglass insulation.

The present binder compositions may be used in methods of binding fibersto make the fiber-containing composites. The fiber-containing compositesmay include fibers of one or more types, such as glass fibers, carbonfibers, and organic polymer fibers, among other types of fibers. Thebinder compositions used to make the composites may include a reducingsugar and a reaction product of a urea compound and analdehyde-containing compound as described herein. The methods mayinclude the step of applying the binder composition to a mat of woven ornon-woven fibers to make a curable binder-fiber amalgam. The curableamalgam is then cured to form the fiber-containing composite of fibersbound together by the cured binder.

The step of applying the binder composition to the fibers may be done bya variety of techniques including spraying, spin-curtain coating,curtain coating, and dipping-roll coating. The composition can beapplied to freshly-formed fibers, or to fibers that have been cooled andprocessed (e.g., cut, coated, sized, etc.). The binder may be providedto the applicator as a premixed composition or may be supplied to theapplicator in separate solutions for the crosslinking agent and thereducing sugar component. In some instances where the binder compositionincludes a solvent, a portion or all of the solvent may be removed fromthe composition before or after its application on the fibers.

The step of curing the binder composition may include exposing thecomposition applied to the fibers to an environment conducive to curing.For example, the curable amalgam of fibers and binder composition may beheated to a binder curing temperature. Exemplary binder curingtemperatures may include a temperature range from 100° C. to 250° C. Thecuring amalgam may be heated to the curing temperature for a period of 1minute to 100 minutes (e.g., 20 minutes).

The curing step may produce the finished fiber-containing composite,such as fiberglass insulation. In some exemplary methods, additionalagents like an anti-dusting agent may be applied during or following thecuring step.

Exemplary Binder Compositions

The present carbohydrate binder compositions may include one or moretypes of carbohydrate, nitrogen-containing compounds, and thickeningagents, among other binder components. When the binder compositions arecured, the carbohydrates and nitrogen-containing compounds form acrosslinked polymer that in some instances is referred to as a Maillardpolymerization product. Thickening agents are selected that createlittle or no interference with the crosslinking reaction of the polymerprecursors so that the binder composition can be thoroughly and quicklycured after deposition on the fiber substrate (e.g., a glass fiber mat).

Exemplary thickening agents are added to control the viscosity of thebinder compositions that are ultimately cured to make the adhesivebinder component of the fiber product. The thickening agents may bepolymeric materials and may be partially or fully water soluble. Theyare selected to enhance the binder compositions rheological properties(e.g., increase the composition's viscosity and surface tension) withoutsubstantially interfering with the composition's curability into anadhesive binder for the substrate fibers. Exemplary thickening agentsmay include polysaccharides, such as xanthan gum, guar gum, modifiedstarches and the like; neutralized polyacrylic acid, such as sodiumpolyacrylate, modified celluloses, such as hydroxyethyl cellulose (HEC),carboxymethyl cellulose (CMC), as well as their soluble salts,polyacrylamides, and polyvinyl alcohols. The exemplary thickening agentsmay have a weight average molecular weight typically from 100,000 to2,000,000 g/mol (e.g., 200,000 to 1,000,000 g/mol). The thickening agent(or agents) are typically added to the binder composition prior to itsdeposition on the fiber substrate, or alternatively may be addedseparately and approximately simultaneously with the other components ofthe binder composition to the fiber substrate.

The concentration of thickening agent in the binder composition maydepend in part on the concentration of the other binder components inthe composition. The carbohydrate binder compositions may be aqueousmixtures or solutions, and their viscosities depend in part on the howmuch the polymer precursors have been diluted by the water. For example,some concentrated binder compositions (e.g., solids concentrations of 45to 70 wt. % or more) may have viscosities in the hundreds of centipoiseat room temperature. The concentrated resins are typically diluted withwater to, for example, a solids concentration of 10 to 30 wt. % solids(e.g., 10 to 20 wt. % solids), reducing the binder composition'sviscosity to less than 3 cPs at room temperature. Other bindercompositions may have functional viscosities at high concentrations(e.g., 20 cPs at 50 wt. % solids concentration) but should be diluted toaddress processing challenges such as LOI, weight, and uniformityproblems for the applied binder composition.

Thickening agents may be added to increase the viscosity of the aqueousbinder composition to a range of 7 to 50 cPs at room temperature (i.e.,20° C.), as measured by a Brookfield viscometer operating at a speed of60 revolutions per minute. Typically, binder composition viscosities inthis range can be achieved at thickening agent concentrations between0.03 to 0.3 wt. % of the total composition. The concentration range ofthickening agent can depend on the type of agent used. For example,adding hydroxyethyl cellulose to a concentration range of 0.05 to 0.3wt. % may be sufficient to increase the composition's viscosity into a 7to 50 cPs range. The same viscosity range may be met by adding 0.03 wt.% to 0.2 wt. % xanthan gum to the aqueous binder composition.

In addition to the thickening agents, the binder compositions may alsocontain a surfactant that provides more precise control over the surfacetension of the composition. The surfactant may be added in amounts toachieve a surface tension for the binder composition of 35 to 50 mN/m(e.g., 38 to 48 mN/m, 40 to 47 mN/m, etc.). These surfactants mayinclude cationic, anionic, and/or non-ionic surfactants.

The binder formulations of the binder compositions may include one ormore types of carbohydrates and nitrogen-containing compounds. Thenitrogen-containing compounds may act as crosslinking agents for thecarbohydrates in the cured binder. The carbohydrates used in the binderformulations may include reducing sugars that contain at least onealdehyde group, or are capable of forming an aldehyde group throughisomerization. Exemplary reducing sugars may include glucose (dextrose),fructose, glyceraldehyde, galactose, allose, xylose, ribose, maltose,cellobiose, and lactose, among others.

The nitrogen-containing compounds may include a variety of compoundsthat can distinguish the class of binder formulation. One class ofbinder formulations uses an amino-amide as the nitrogen containingcompound, which itself is a reaction product of an amine with asaturated or unsaturated reactant. Another class of binder formulationshas as the nitrogen-containing compound a reaction product of a ureacompound and aldehyde-containing compound. Each of these classes ofnitrogen-containing compounds are described more detail below.

1. Carbohydrate/Amino-Amide Binder Formulations

The nitrogen-containing compounds may include amines capable ofundergoing conjugate addition with a saturated or unsaturated reactantto form an amino-amide. The amino-amide then reacts during curing withthe carbohydrate to form a polyimide. The amino-amide addition productsmay be formed by mixing the amine and saturated or unsaturated reactantin an aqueous medium at room temperature. The resulting additionproducts are either water-soluble, water-dispersible, or are present asan emulsion. In some binder formulations, the formation of theamino-amide from the reaction of the amine precursor with the saturatedor unsaturated reactant may occur before the introduction of thecarbohydrate, while other formulations mix all three precursors (i.e.,the amine, saturated or unsaturated reactant, and carbohydrate) beforethe amino-amide is formed.

Each amine may have two or more primary and/or secondary amine groups toreact and crosslink two or more carbohydrate molecules. The amines mayinclude aliphatic, cycloaliphatic and aromatic amines. They may belinear or branched, and have additional functionalities and linkagessuch as alcohols, thiols, esters, amides, acids, and ethers, amongothers. Exemplary amines may include 1,2-diethylamine,1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine,1,6-hexanediamine, diaminoxylene, diethylenetriamine,triethylenetetramine, tetraethylenepentamine, as well as combinations oftwo or more of these amines. Natural and synthetic amino acids such aslysine, anginine, hestidine, etc., may also be used.

The curable amino-amide is formed through the selection of anunsaturated or saturated reactant that is an anhydride, carboxylic acid,ester, and salts and mixtures of such reactants. These unsaturatedreactants may include maleic acid, fumaric acid, maleic anhydride, mono-and di-esters of maleic acid and fumaric acid, and salts and mixtures ofthese. Ammonium salts of the unsaturated acids of their monoestersconveniently can be utilized. Saturated reactants may include, withoutlimitation, succinic anhydride, succinic acid, mono and diesters ofsuccinic acid, glutaric acid and anhydride, phthalic acid and anhydride,tetrahydro phthalic acid and anhydride, mono and diesters of acidanhydrides and salts of the acids, and their mono esters.

In some formulations, the amino-amide product may be oligomerized beforereacting with the carbohydrate. This oligomerization may be facilitatedby heating the amino-amide solution until the amino-amide is dimerized,trimerized, tetramerized, etc., into the amino-amide oligomer. Theheating conditions may include raising the temperature of theamino-amide solution to, for example, 120° C. to 150° C. for a time ofup to 5 hours. In some instances, the oligomerized amino-amide productforms a stronger, more rigid cured binder product than then amino-amidemonomer.

Then during the binder curing step, the majority of the carbohydratereacts with the amino-amide intermediate, which contains an amic acidfunctional group, (i.e., an amide linkage in the vicinity of acarboxylic acid). An amic acid functional group is typically morereactive than a simple carboxylic acid. The amount of carbohydrate addedis generally such that the molar ratio of carboxylic acid in theamino-amide to carbonyl or ketone in the carbohydrate is from 1:5 to50:1, for example a ratio of 1:20 to 20:1, or a ratio of 1:10 to 10:1.Additional details about carbohydrate/amino-amide binder formulation aredescribed in co-assigned U.S. patent application Ser. No. 12/539,263 toShooshtari et al, filed Aug. 11, 2009, and titled “Curable FiberglassBinder,” the entire contents of which are herein incorporated byreference for all purposes.

2. Carbohydrate/Urea Derivative Binder Formulations

The nitrogen-containing compounds may include urea derivative reactionproducts of urea (i.e., H₂N—CO—NH₂), and/or substituted ureas, withdiformaldehyde compounds such as glyoxal. One specific class of theseurea derivatives include imidazolidine compounds such as4,5-dihydroxyimidazolidin-2-one, which has the chemical structure:

More specifically, the urea compound may be a substituted orunsubstituted urea having the formula:

where R₁, R₂, R₃, and R₄ are independently chosen from a hydrogen moiety(H), an alkyl group, an aromatic group, an alcohol group, an aldehydegroup, a ketone group, a carboxylic acid group, and an alkoxy group.Exemplary alkyl groups include straight-chained, branched, or cyclichydrocarbons of varying size (e.g., C₁-C₁₂, C₁-C₈, C₁-C₄, etc.).Exemplary aromatic (i.e., aryl) groups include substituted orunsubstituted phenyl moieties, among other aromatic constituents.Exemplary alcohol groups include —ROH, where R may be a substituted orunsubstituted, saturated or unsaturated, branched or unbranched, cyclicor acyclic, organic moiety. For example, R may be —(CH2)_(n)—, where nmay be 1 to 12. Exemplary alcohols may also include polyols having twoor more hydroxyl groups (—OH) in alcohol group. Exemplary aldehydegroups include —RC(═O)H, where R may be a monovalent functional group(e.g., a single bond), or a substituted or unsubstituted, saturated orunsaturated, branched or unbranched, cyclic or acyclic, organic moiety,such as —(CH2)_(n)—, where n may be 1 to 12. Exemplary ketone groups mayinclude —RC(═O)R′ where R and R′ can be variety of carbon containingconstituents. Exemplary carboxylic acid groups may include —R—COOH,where R may be a monovalent functional group, such as a single bond, ora variety of carbon-containing constituents. Exemplary alkoxy groupsinclude —OR_(x), where R_(x) is an alkyl group.

The aldehyde-containing compound may contain one or more aldehydefunctional groups. Exemplary aldehyde-containing compounds includeacetaldehyde, propanaldehyde, butyraldehyde, acrolein, furfural,glyoxal, gluteraldehyde, and polyfurfural among others. Exemplaryaldehyde-containing compounds may also include substituted glyoxalcompounds having the formula:

where R₅ and R₆ may be independently hydrogen (H), an alkyl group, anaromatic group, an alcohol group, an aldehyde group, a ketone group, acarboxylic acid group, and an alkoxy group, among other groups.

The reaction products of the urea compound and the aldehyde-containingcompound may include an imidazolidine compound having the formula:

where R₇, R₈, R₉, and R₁₀ are independently, —H, —OH, —NH₂, an alkylgroup, an aromatic group, an alcohol group, an aldehyde group, a ketonegroup, a carboxylic acid group, and an alkoxy group. In one specificexample of the reaction between urea and glyoxal, the reaction productmay be 4,5-dihydroxyimidazolidin-2-one.

The carbohydrate/urea derivative binder formulations may also includeone or more catalysts to increase the rate of the crosslinking reactionsbetween the carbohydrates and crosslinking agents when the compositionis exposed to curing conditions. Exemplary catalysts may includealkaline catalysts and acidic catalysts. The acidic catalysts mayinclude Lewis acids (including latent acids and metallic salts), as wellas protic acids, among other types of acid catalysts. Lewis acidcatalysts may include a salt of a deprotonized anion such as a sulfate,sulfite, nitrate, nitrite, phosphate, halide, or oxyhalide anion incombination with one or more metallic cations such as aluminum, zinc,iron, copper, magnesium, tin, zirconium, and titanium. Exemplary Lewisacid catalysts include aluminum sulfate, ferric sulfate, aluminumchloride, ferric chloride, aluminum phosphate, ferric phosphate, andsodium hypophosphite (SHP), among others. Exemplary latent acids includeacid salts such as ammonium sulfate, ammonium hydrogen sulfate, mono anddibasic ammonium phosphate, ammonium chloride, and ammonium nitrate,among other latent acid catalysts. Exemplary metallic salts may includeorgano-titanates and organo-zirconates (such as those commerciallymanufactured under the tradename Tyzor® by DuPont), organo-tin, andorgano-aluminum salts, among other types of metallic salts. Exemplaryprotic acids include sulfuric acid, phosphoric acid, hydrochloric acid,nitric acid, sulfonic acid compounds (i.e., R—S(═O)₂—OH) such asp-toluenesulfonic acid and methanesulfonic acid, and carboxylic acids,among other protic acids. Catalyst compositions may also includecombinations of two or more catalysts, for example the combination ofammonium sulfate and diammonium phosphate.

The pH of the present binder compositions may vary depending upon thetypes and relative concentrations of the components used. Typically thepH of the present binder compositions are slightly acidic to alkalinewith a pH range of about 6 to 8 (e.g., 6.5 to 7.5). The bindercompositions have a pH that creates relatively little or no acid-basedcorrosion of metal fabrication equipment.

The reaction product of the urea derivative nitrogen-containing compoundacts as a crosslinking agent for the carbohydrate. During a curingstage, the urea derivative can bond to two or more carbohydrates (eitherpolymerized or unpolymerized) to form a crosslinked, polymeric curedbinder.

The molar ratio of the (1) crosslinking reaction product of the ureacompound and the aldehyde-containing compound to (2) the carbohydrategenerally ranges from 1:2 to 1:50. Exemplary ratios of crosslinkingagent to carbohydrate include a range from 1:4 to 1:10. Additionaldetails about carbohydrate/urea derivative binder formulations aredescribed in co-assigned U.S. patent application Ser. No. 13/490,638 toShooshtari et al, filed Jun. 7, 2012, and titled “Formaldehyde-FreeBinder Compositions with Urea-Formaldehyde Reaction Products,” theentire contents of which are herein incorporated by reference for allpurposes.

3. Carbohydrate/Nitrogen-Containing Salt Binder Formulations

i. Salts of Inorganic Acids with Amines

In additional carbohydrate binder formulations, the nitrogen-containingcompounds may include a nitrogen-containing salt. For example, thenitrogen-containing compound may include the salt product of thecombination of an inorganic acid and an amine (e.g., an amine-acidsalt). Exemplary inorganic acids may include a phosphorous-containingacid such as phosphoric acid, pyrophosphoric acid, phosphorous acid, andphosphine, among others. Exemplary inorganic acids may also includeoxygenated inorganic acids such as sulfuric acid, sulfurous acid, nitricacid, boric acid, hypochloric acid, chlorate acid, among others. Theymay also include non-oxygenated inorganic acids such as hydrochloricacid and hydrogen sulfide, among others.

Exemplary amines may include polyamines (e.g., diamines, triamines,etc.) having at least one primary amine group. For example, the aminesmay include ethylene diamine, 1,3-propanediamine, 1,4-butanediamine,1,5-pentanediamine, 1,6-hexanediamine, α, α′-diaminoxylene,diethylenetriamine, triethylenetetramine, tetraethylenepentamine, aswell as combinations of two or more of these amines.

When the amine-acid salt reacts with the carbohydrate under bindercuring conditions the binder is formed. Exemplary binder systems includethe combination of an amine-acid salt of 1,6-hexanediamine andphosphoric acid with the carbohydrate dextrose (HPD), the combination ofan amine-acid salt formed from the combination of ethylene diamine andphosphoric acid with dextrose (EPD). Additional details about theseamine-acid salt and carbohydrate binder formulations are described inco-assigned U.S. patent application Ser. No. 12/539,211, filed Aug. 11,2009 to Shooshtari, the entire contents of which are herein incorporatedby reference for all purposes.

ii. Salts of Inorganic Acids with Amines and Organic Species

Some carbohydrate/amine-acid salt binder formulations further includesome combination of an organic acid, organic anhydride, and/or analkanol amine. Exemplary organic acids may include polycarboxylic acidsuch as citric acid and or maleic acid. Exemplary organic anhydrides mayinclude maleic anhydride, phthalic anhydride, methylphthalic anhydride,glutaric anhydride, tetrahydrophthalic anhydride, perhydrophthalicanhydride, itaconic anhydride, succinic anhydride, and trimelliticanhydride, among other anhydrides.

Exemplary alkanol amines may have the formula:

where R₁, R₂, and R₃ are independently chosen from, a hydrogen, a C₁₋₁₀alkyl group, an aromatic group, and a C₁₋₁₀ hydroxy alkyl group, andwherein at least one of R₁, R₂, and R₃ is a hydroxyl alkyl group.

Specific examples of alkanol amines may include methanol amines such asmono-, di-, and tri-, methanol amine; ethanol amines such as monoethanolamine (MEA), diethanol amine (DEA), and triethanol amine (TEA);isopropanol amines such as mono-, di-, and tri-, isopropanol amine;methyldiethanol amine; ethyldiethanol amine; propyldiethanol amine;isopropyldiethanol amine; and n-butyldiethanol amine, among others.

Exemplary carbohydrate binder formulations may include the combinationof a carbohydrate, amine-acid salt, and organic acid. These includebinder formulations of dextrose, ethylene diamine phosphate, and citricor maleic acid. Additional details about these carbohydrate/amine-acidsalt/organic acid binder formulations are described in co-assigned U.S.patent application Ser. No. 13/478,765, filed May 23, 2012 to Shooshtariet al., the entire contents of which are herein incorporated byreference for all purposes.

Exemplary carbohydrate binder formulations may also include thecombination of a carbohydrate, amine-acid salt, organic anhydride, andalkanol amine. This include binder formulations of the reaction productsof monoethanol amine (“E”) and maleic anhydride (“M”) combined withethylenediamine phosphate (“EP”) and dextrose (“D”) to make bindercompositions referred to as EMEPDs. In still other exemplary binderformulations, the amine-acid salt may be eliminated. This includesformulations of the reaction products of monoethanol amine (“E”) andmaleic anhydride (“M”) with the carbohydrate dextrose to make bindercompositions referred to as EMDs. Additional details about thesecarbohydrate/amine-acid salt/anhydride-alkanol amine binder formulationsare described in co-assigned U.S. patent application Ser. No.13/559,769, filed Jul. 27, 2012 to Shooshtari et al., the entirecontents of which are herein incorporated by reference for all purposes.

Exemplary binder formulations may include additional compounds combinedwith the reducing sugar, organic acid, and amine salt of an inorganicacid. For example, urea may also be included with the other bindercomponents. Exemplary, urea-containing binder compositions may includeethylene diamine phosphate (“EP”), citric acid (“C”), urea (“U”), anddextrose (“D”) combined to make a binder composition referred to asEPCUD. Exemplary molar ratios of these components may includeEthylenediamine:Phosphoric Acid:Citric Acid:Urea:Dextrose of1:1:0.5:1:6.

iii. Ammonium Salts of Carboxylic Acids

In still additional carbohydrate binder formulations, thenitrogen-containing compounds may include an ammonium salt of apolycarboxylic acid. Exemplary ammonium salts of polycarboxylic acidsmay be formed from the reaction of ammonia (NH₃) with the polycarboxylicacid to form the ammonium salt. It should be appreciated that othertypes of ammonium ions can function as the cation in theammonium-polycarboxylate salt, such as (NH₃R₁)⁺, (NH₂R₁R₂)⁺, and(NHR₁R₂R₃)⁺, where R₁, R₂, and R₃ are each independently chosen from analkyl, cycloalkyl, alkenyl, cycloalkenyl, hetrocyclyl, aryl, andheteroaryl, among other organic groups.

Exemplary polycarboxylic acids may include dicarboxylic acids,tricarboxylic acids, etc. Dicarboxylic acids may include maleic acid,and tricarboxylic acids may include citric acid.

The binder formulations may include the combination of a carbohydrate(e.g., a reducing sugar) with the ammonium salt of the polycarboxylicacid. For example, the binder composition may include dextrose andtriammonium citrate.

4. Carbohydrate Blends with Latex and/or Solution Polymers

This group of carbohydrate binder compositions is distinguished by theinclusion of the components of a second binder in the formulation. Thesecond binder may be a latex binder and/or solution polymer with asignificantly higher viscosity than the carbohydrate binder composition.In some instances, the second binder may act as the sole thickeningagent in the carbohydrate binder composition, while in other instancesthe second binder may complement other thickening agents to get thecomposition to a target viscosity.

The second binder may include latex binders having a Brookfieldviscosity of about 100 cPs or more (spindle 18 operating at a speed of60 rpm) at 20° C. Exemplary second binders may include acrylic binders,among others. The second binder may be present up to about half theweight of the total binder composition (e.g., 1 to 50 wt. %; 1 to 20 wt.%; etc.).

5. Additional Binder Components

The present carbohydrate binder compositions may further include one ormore additional components such as adhesion prompters, oxygenscavengers, solvents, emulsifiers, pigments, organic and/or inorganicfillers, flame retardants, anti-migration aids, coalescent aids, curingcatalysts, wetting agents, biocides, plasticizers, organosilanes,anti-foaming agents, colorants, waxes, suspending agents, anti-oxidants,and secondary crosslinkers, among other components. In some instances,some or all of the additional components are pre-mixed with the bindercomposition before it is applied to fibers and cured. In additionalinstances, some or all of the additional components may be introduced tothe curable, curing, and/or cured fiber-containing composite during orafter the initial binder composition is applied to the fibers.

In the preceding description, for the purposes of explanation, numerousdetails have been set forth in order to provide an understanding ofvarious embodiments of the present technology. It will be apparent toone skilled in the art, however, that certain embodiments may bepracticed without some of these details, or with additional details.

Having described several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theinvention. Additionally, a number of well-known processes and elementshave not been described in order to avoid unnecessarily obscuring thepresent invention. Additionally, details of any specific embodiment maynot always be present in variations of that embodiment or may be addedto other embodiments.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimits of that range is also specifically disclosed. Each smaller rangebetween any stated value or intervening value in a stated range and anyother stated or intervening value in that stated range is encompassed.The upper and lower limits of these smaller ranges may independently beincluded or excluded in the range, and each range where either, neither,or both limits are included in the smaller ranges is also encompassedwithin the invention, subject to any specifically excluded limit in thestated range. Where the stated range includes one or both of the limits,ranges excluding either or both of those included limits are alsoincluded.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural referents unless the context clearly dictatesotherwise. Thus, for example, reference to “a method” includes aplurality of such methods and reference to “the salt” includes referenceto one or more salts and equivalents thereof known to those skilled inthe art, and so forth. The invention has now been described in detailfor the purposes of clarity and understanding. However, it will beappreciated that certain changes and modifications may be practicewithin the scope of the appended claims.

What is claimed is:
 1. A carbohydrate binder composition comprising: acarbohydrate; a nitrogen-containing compound; a catalyst that catalyzesa reaction between the carbohydrate and the nitrogen-containingcompound, wherein the catalyst is water soluble in the composition butbecomes water insoluble after curing the composition; and a counter ionformed by a reaction of an acid with a base comprising ammonia, asubstituted amine, or a polyamine.
 2. The composition of claim 1,wherein curing the composition comprises heating the composition to atemperature from 100° C. to 250° C.
 3. The composition of claim 1,wherein the catalyst comprises a sulfate, sulfonate, phosphate, orphosphonate moiety.
 4. The composition of claim 1, wherein the catalystcomprises a polymer comprising a sulfate, sulfonate, phosphate, orphosphonate moiety.
 5. The composition of claim 1, wherein the catalystis selected from the group consisting of a sulfonated polystyrene, asulfonated styrene maleic anhydride, a sulfonated polyethylene, asulfonated polypropylene, a phosphonated polystyrene, a phosphonatedstyrene maleic anhydride, a phosphanated polyethylene, and aphosphanated polypropylene.
 6. The composition of claim 1, wherein thecatalyst is a sulfated oligomer, a sulfonated oligomer, a phosphateoligomer, or a phosphanated oligomer.
 7. The composition of claim 1,wherein the catalyst is a sulfonated or phosphanated polymer with amolecular weight of about 20,000 g/mol or more, and the composition isneutralized with a base to a pH from about 7 to about
 10. 8. Thecomposition of claim 1, wherein: the base comprises the substitutedamine, and the substituted amine comprises an aliphatic mono-substitutedamine, an aliphatic di-substituted amine, an aliphatic tri-substitutedamine, an aromatic mono-substituted amine, an aromatic di-substitutedamine, or an aromatic tri-substituted amine.
 9. The composition of claim1, wherein the catalyst is a first catalyst, further comprising a saltcatalyst or salt catalysts, wherein: the salt catalyst or salt catalystscatalyze the reaction between the carbohydrate and thenitrogen-containing compound, the salt catalyst or salt catalystscomprise sulfate, nitrate, or phosphate salts, and the salt catalyst orsalt catalysts in the composition have a total weight no more thanone-ninth the weight of the first catalyst on a dry basis.
 10. Acarbohydrate binder composition comprising: a carbohydrate; anitrogen-containing compound; and a catalyst that catalyzes a reactionbetween the carbohydrate and the nitrogen-containing compound, wherein:the catalyst is water soluble in the composition but becomes waterinsoluble after curing the composition, and the catalyst is a sulfatedepoxy, a sulfonated epoxy, a phosphate epoxy, or a phosphonated epoxy.11. The composition of claim 10, wherein the catalyst comprises areaction product of one mole of an epoxy compound having one or moreepoxide moieties and one mole of sulfuric acid or phosphoric acid foreach epoxide moiety.
 12. The composition of claim 11, wherein the epoxycompound is selected from the group consisting of an epoxidized plantoil, an epoxidized polyether, a bisphenol-A epoxy, a bisphenol-F epoxy,a resole epoxy, and a novolac epoxy.
 13. The composition of claim 11,wherein the epoxy compound is an epoxidized soybean oil or an epoxidizedlinseed oil.
 14. The composition of claim 10, wherein the catalystcomprises sulfated bisphenol-A epoxy.
 15. The composition of claim 10,wherein the catalyst comprises phosphated epoxidized plant oil.